土质滑坡发育概率与坡度间关系研究

STATISTIC RELATIONSHIP BETWEEN SLOPE GRADIENT AND LANDSLIDE PROBABILITY IN SOIL SLOPES AROUND RESERVOIR

坡度是土质滑坡发育的一个重要内在因素。对构皮滩库区的113个土质滑坡(潜在滑坡)发育的原始坡度进行统计分析,发现滑坡的坡度分布具有正态分布特征,并运用χ2检验方法也验证了库区内滑坡坡度分布服从正态分布,建立了坡度与滑坡发育概率间的函数关系。根据该函数关系,计算出滑坡在不同坡度区间内滑坡发育概率,并将研究区内滑坡发育概率分为3类:坡度为25.0°～45.0°,滑坡发育概率最高,为60.47%;坡度为18.0°～25.0°和45.0°～51.0°,滑坡发育概率中等,为25.46%;坡度大于51.0°及小于18.0°的坡体,滑坡发育概率最低,为14.07%。研究结果与实际调查的情况吻合较好,可为构皮滩库区内滑坡防治规划提供依据,为滑坡灾害危险度评价中指标的量化和权重的确定提供新思路。

Slope gradient is one of indispensable internal factor during the development process of landslides.After counting and analyzing a great deal of gradients at 113 soil landslides in Goupitan reservoir area,we find that the distribution of gradients have the characteristics of the normal distribution.Using Chi-square test,we verify the gradients of landslides follow normal distribution and establish the function that reflect the relationship between gradient and probability of soil landslides.According to the relationship,we calculate the probability of landslide in different gradient ranges.We then divide the probability into three kinds.The gradients of 25.0° ～ 45.0°have the maximum probability to soil landslides,which accounts for 60.47% of the total landslides.The gradients of 18.0° ～ 25.0° and 45.0° ～ 51.0°have the middle probability to soil landslides,which accounts for 25.46%.The gradients less than 18.0°or more than 51.0°have the minimum probability to soil landslides,which accounts for 14.07%.The research result inosculates preferably with the fact.The result of this paper not only provides potent gist to the construction of Goupitan reservoir area in future,but also provides a new idea to determine the weighting and index quantification in the process of assessment the landslide danger degree.